MODELLING DUNE EROSION, OVERWASH AND INUNDATION OF BARRIER ISLANDS

Bas Hoonhout, Jaap van Thiel de Vries

Abstract


Physical model experiments are performed at Deltares to investigate the morphological response of barrier islands on extreme storm events. The experiments included dune erosion, overwash and inundation regimes. Extensive measurement techniques made detailed comparison with numerical models possible. This paper describes the comparison between the physical model results and the numerical morphodynamic model XBeach. It appeared that XBeach simulates the main characteristics in hydro- and morphodynamics at profiles with shallow foreshores, which are characteristic for barrier islands, well. However, the absolute results of especially the overwash experiments still do not agree with the measurements. It is expected that several generic issues regarding small-scale physical model experiments are of influence here. Nevertheless, calibration of the XBeach model seems to be necessary for shallow profiles. Especially the calibration of the wave characteristics on the shallow foreshore, related to the morphodynamics is far from trivial.

Keywords


dune erosion; physical modeling; barrier islands; erosion; overwash; inundation

References


[Baldock et al., 1998] Baldock, T. E., Holmes, P., Bunker, S., and Van Weert, P. (1998). Crossshore hydrodynamics within an unsaturated surf zone. Coastal Engineering, 56:1133–1152.

[Battjes and Janssen, 1978] Battjes, J. A. and Janssen, J. P. F. M. (1978). Energy loss and set-up due to breaking of random waves. In Proceedings 16th International Conference on Coastal Engineering, pages 570–587, New York. ASCE.

[Battjes and Stive, 1985] Battjes, J. A. and Stive, M. J. F. (1985). Calibration and verification of a dissipation model for random breaking waves. Journal of Geophysical Research, 90:9159–9167.http://dx.doi.org/10.1029/JC090iC05p09159

[Daly et al., 2011] Daly, C., Roelvink, J. A., Van Dongeren, A. R., Van Thiel de Vries, J. S. M., and McCall, R. T. (2011). Validation of an advective-deterministic approach to short wave breaking in a surf-beat model. Coastal Engineering. In Press.

[Deltares, 2011] Deltares (2011). Dune erosion and overwash at wide beaches - part b: measurement results of experiments in the scheldt flume. Report 1202124-007-HYE-0005, Deltares.

[Janssen and Battjes, 2007] Janssen, T. T. and Battjes, J. A. (2007). A note on wave energy dissipation over steep beaches. Coastal Engineering, 45:711–716.http://dx.doi.org/10.1016/j.coastaleng.2007.05.006

[McCall et al., 2011] McCall, R. T., Van Geer, P. F. C., and Hoonhout, B. M. (2011). Physical modeling of storm-induced erosion and overwash. In Proceedings 7th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes, Miami, Florida.

[Roelvink, 1993] Roelvink, J. A. (1993). Dissipation in random wave groups incident on a beach. Coastal Engineering, 19:127–150.http://dx.doi.org/10.1016/0378-3839(93)90021-Y

[Roelvink et al., 2009] Roelvink, J. A., Reniers, A. J. H. M., Van Dongeren, A. R., Van Thiel de Vries, J. S. M., McCall, R. T., and Lescinski, J. M. (2009). Modelling storm impacts on beaches, dunes and barrier islands. Coastal Engineering, 56(11-12):1133–1152.http://dx.doi.org/10.1016/j.coastaleng.2009.08.006

[Ruessink et al., 2003] Ruessink, B. G., Walstra, D. J. R., and Southgate, H. N. (2003). Calibration and verification of a parametric wave model on barred beaches. Coastal Engineering, 48:139– 149.http://dx.doi.org/10.1016/S0378-3839(03)00023-1

[Sallenger, 2000] Sallenger, A. H. (2000). Storm impact scale for barrier islands. Journal of Coastal Research, 16(3):860–895.

[Soulsby, 1997] Soulsby, R. L. (1997). Dynamics of Marine Sands. Thomas Telford, London. [Steetzel and Visser, 1992] Steetzel, H. J. and Visser, P. J. (1992). Profile development of dunes due to overflowprofile development of dunes due to overflow. In Proceedings 23rd Coastal Engineering Conference, pages 2669–2679. ASCE.

[Van Rijn, 2007] Van Rijn, L. C. (2007). Unified view of sediment transport by currents and waves, part i, ii, iii and iv. Journal of Hydraulic Engineering, 133:649–689 (part I & II), 761–793 (part III & IV).

[Van Thiel de Vries, 2009] Van Thiel de Vries, J. S. M. (2009). Dune erosion during storm surges. PhD thesis, Delft University of Technology.

[Vellinga, 1986] Vellinga, P. (1986). Beach and Dune Erosion during Storm Surges. PhD thesis, Delft University of Technology.

[Vreugdenhil, 1989] Vreugdenhil, C. B. (1989). Computational Hydraulics - An Introduction. Springer-Verlag, Berlin.http://dx.doi.org/10.1007/978-3-642-95578-5


Full Text: PDF

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.